A Palladium Wall Coated Microcapillary Reactor for Use in Continuous Flow Transfer Hydrogenation

Herein we describe the preparation of a novel continuous flow multi‐channel microreactor in which the internal surface has been functionalised with a palladium coating, enabling its use in catalytic heterogeneous liquid‐phase reactions. Simple chemical deposition techniques were used to immobilise palladium(0) on the channel wall surface of a polymeric multi‐capillary extrudate made from ethylene‐vinyl alcohol copolymer. The Pd coating of the microcapillaries has been characterised by mass spectrometry and light and electron microscopy. The functional activity of the catalytic Pd layer was tested in a series of transfer hydrogenation reactions using triethylsilane as the hydrogen source.     

Comparing intracellular stability and targeting of sulfobetaine quantum dots with other surface chemistries in live cells

The in vivo labeling of intracellular components with quantum dots (QDs) is very limited because of QD aggregation in the cell cytoplasm and/or QD confinement into lysosomal compartments. In order to improve intracellular targeting with QDs, various surface chemistries and delivery methods have been explored, but they have not yet been compared systematically with respect to the QD intracellular stability. In this work, the intracellular aggregation kinetics of QDs for three different surface chemistries based on ligand exchange or encapsulation with amphiphilic polymers are compared. For each surface chemistry, three delivery methods for bringing the nanoparticles into the cells are compared: electroporation, microinjection, and pinocytosis. It is concluded that the QD intracellular aggregation behavior is strongly dependent on the surface chemistry. QDs coated with dihydrolipoic acid-sulfobetaine (DHLA-SB) ligands diffuse freely in cells for longer periods of time than for QDs in the other chemistries tested, and they can access all cytoplasmic compartments. Even when conjugated to streptavidin, these DHLA-SB QDs remain freely diffusing inside the cytoplasm and unaggregated, and they are able to reach a biotinylated target inside HeLa cells. Such labeling was more efficient when compared to commercial streptavidin-conjugated QDs, which may be due to the smaller size of DHLA-SB QDs and/or to their superior intracellular stability.     

Deployment status and common technical specifications for a B-PONsystem

Broadband passive optical networks (B-PONs) have entered the commercial deployment phase in North America, Japan, and Europe. Nippon Telegraph and Telephone, BellSouth, France Telecom, British Telecommunications p.l.c., and SBC have developed a set of common technical specifications (CTS) for a B-PON system based on ITU-T Recommendations G.983.1, G.983.2 and G.983.3. They have deployed or plan to deploy B-PON systems based on this CTS. This article describes B-PON interface features, the outline of the CTS, and the deployment status of the B-PON systems around the world     

Beam misalignments and fluid velocities in laser-induced thermal acoustics

Beam misalignments and bulk fluid velocities can influence the time history and intensity of laser-induced thermal acoustics (LITA) signals. A closed-form analytic expression for LITA signals incorporating these effects is derived, allowing the magnitude of beam misalignment and velocity to be inferred from the signal shape. It is demonstrated how instantaneous, nonintrusive, and remote measurement of sound speed and velocity (Mach number) can be inferred simultaneously from homodyne-detected LITA signals. The effects of different forms of beam misalignment are explored experimentally and compared with theory, with good agreement, allowing the amount of misalignment to be measured from the LITA signal. This capability could be used to correct experimental misalignments and account for the effects of misalignment in other LITA measurements. It is shown that small beam misalignments have no influence on the accuracy or repeatability of sound speed measurements with LITA.     

Animation‐Aware Quadrangulation

Geometric meshes that model animated characters must be designed while taking into account the deformations that the shape will undergo during animation. We analyze an input sequence of meshes with point‐to‐point correspondence, and we automatically produce a quadrangular mesh that fits well the input animation. We first analyze the local deformation that the surface undergoes at each point, and we initialize a cross field that remains as aligned as possible to the principal directions of deformation throughout the sequence. We then smooth this cross field based on an energy that uses a weighted combination of the initial field and the local amount of stretch. Finally, we compute a field‐aligned quadrangulation with an off‐the‐shelf method. Our technique is fast and very simple to implement, and it significantly improves the quality of the output quad mesh and its suitability for character animation, compared to creating the quad mesh based on a single pose. We present experimental results and comparisons with a state‐of‐the‐art quadrangulation method, on both sequences from 3D scanning and synthetic sequences obtained by a rough animation of a triangulated model.     

Visualization of eclipses and planetary conjunction events. The interplay between model coherence, scaling and animation

The problem of an instructive and realistic animation and visualization of the shadow- and color-conditions during conjunctions of actively and passively illuminated cosmic objects has found only particularly satisfying solutions so far. As an example we study a total solar eclipse. There are didactic shortcomings of specialized astronomical software, even though solutions have been given, which are very impressive for experts. Using the possibilities of commercial 3D-animation software we give an object-oriented partial solution. In order to get correct astronomical representations we model – for different tasks – the object space under cinematic aspects with parameters for spatial and temporal scaling, for illumination and coloring under couplings of varying strength. The adaptation of the parameters to optimal acceptance of the spectator must be done a posteriori.